1. Field of the Invention
The present invention relates generally to valve assemblies, and more particularly, to a rapid acting, fully balanced valve assembly having particularly advantageous O-ring seal carrying valve members.
2. Description of the Prior Art:
Numerous applications presently exist for valves and valve assemblies capable of high capacity, utra-fast slow control of any of various fluids such as water, oil, gas, air, steam and the like. Such valve assemblies, in order to be economically feasible and commercially acceptable, must be capable of rapidly diverting or controlling fluid flow in response to the input of only a slight amount of mechanical force, power or energy to move the control stem. In addition, it is often desirable that the valve assemblies be light weight and minimally complex. This, of course, has the inherent advantage of minimizing both initial construction costs as well as subsequent maintenance outlays while at the same time decreasing unproductive down time of overall systems incorporating such a valve assembly.
While the prior art, as exemplified by U.S. Pat. Nos. 2,656,144, 2,702,049, 3,049,239, 3,191,626, and 3,338,550, is generally cognizant of various valve assemblies capable of both mechanical and electrical actuation and balanced for at least certain fluid flow conditions, these types of valve arrangements have not proven to be fully satisfactory in that they are typically complex, are prone to valve damage after repeated operation, do not hold pressure well in both flow directions, aer incapable of extremely rapid operation, and require many complex parts which are not easily manufactured.
The desirable characteristics of a valve assembly for general use have long been well known as well as the various undersirable characteristics and disadvantages exhibited generally by the prior art. Nevertheless, and despite the fact that many new valve designs have been attempted in the past and are presently being attempted in an effort to solve these deficiencies, there has heretofore been unavailable a simple, efficient, and economical valve structure capable of rapidly controlling substantial fluid flow situations with ony a minimum of energy input. In addition, while attempts have been made in the past to provide valve assemblies with O-ring seals capable of extended use, full realization of the dynamics of an O-ring seal has hindered valve designers and engineers from developing in the past a valve assembly exhibiting vastly superior O-ring seal wear characteristics.